Define the style and type of lesson plan you want. The type of lesson plan depends on, among other things, the size of your class, how deep you want to get into headline writing, the time you have to spend on this topic, your students' preexisting knowledge and experience with headline writing and journalism, the style of headline writing you'd like to teach and the education level of your students (high school, college, graduate, etc.).
Search on mainstream news media websites such as The New York Times for lesson plans, tips and guides. Many leading news sources foster correct journalism techniques and styles by educating readers on the basics of the trade.
Tailor the lesson plans you find to match any criteria they don't meet already. This can mean taking out an activity, spending more time on individual points and topics or creating new sections that incorporate your teaching goals.